<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			//、输入月份，显示当月的天数（使用case 穿透简化代码）1-12
			var month =prompt("输入月份")*1 ;
			switch (month) {
				case 1:
				case 3:
				case 5:
				case 7:
				case 8:
				case 10:
				case 12:
					console.log(month + '月份有31天');
					break;
				case 2:
					console.log(month + '月份有29天，平年有28天呢');
					break;
				case 4:
				case 6:
				case 9:
				case 11:
					console.log(month + '月份有30天');
					break;
					default:
					console.log('亲，一年只有12个月呐');
					
			}
		</script>
	</body>
</html>
